seam-craft Skill for Claude: HyperFrames Seam Render Rules

seam-craft tells Claude how to set up a HyperFrames master timeline so scene transitions render without a white flash.

Installs: 60.5K; on skills.sh
Stars: 77.1K; on GitHub
Updated: Nov 2026; last repo commit

This skill comes from HeyGen's HyperFrames repo, where it is marked internal. It covers render correctness, not which transition to pick. The main rule is that the #root element needs an opaque background, because a cut can open a moment where two scene wrappers add up to less than full opacity and the page behind shows through.

It also describes how the injector applies a transition at a scene boundary and lists the placeholder tokens used in transition templates. Its text points to the transition registry for individual transitions. It is one SKILL.md file with no scripts.

Good for

People assembling a multi-scene HyperFrames master timeline
Anyone seeing a white flash at a cut on a dark film
Maintainers of tools that inject transitions into index.html

Install seam-craft

Claude Code

Copy this prompt.

Install the seam-craft skill in Claude Code. Run this command:

INSTALL_INTERNAL_SKILLS=1 npx skills add heygen-com/hyperframes --skill motion-doctrine --skill cut-the-curve --skill seam-craft --skill oversized-cursor --skill captions-overlay -a claude-code

Then check that it loaded and tell me how to use it.

2
Paste it into Claude Code. It shows the change and asks before running it.

Requires Node.js.

The README says these six skills (motion-doctrine, cut-the-curve, seam-craft, oversized-cursor, captions-overlay, changelog-video) are repo-internal and left out of the default install. The skills CLI docs say a skill marked internal: true is hidden unless INSTALL_INTERNAL_SKILLS=1 is set, and all six are marked that way, so the command carries that variable. We have not run it against this repo: run npx skills list afterwards to confirm each skill is there. The plain command shown on skills.sh does not set the variable, so do not rely on it. The skills lean on the upstream /hyperframes skill, which npx hyperframes skills update installs (the README's core set). On Windows, set the variable in your shell first.

From the vendor's docs. Source.

What's in the skill

When it loads

Render-correctness doctrine for scene-to-scene seams in HyperFrames launch videos — the prerequisites that make transitions composite correctly on the master timeline. Load when assembling the master timeline / index.html, when a white flash appears at a cut or crossfade seam (especially on dark films), when reasoning about why a transition opacity dip shows through, or when verifying the render-side mechanics of how overlapping scene wrappers blend. Covers the opaque stage-ground (#root background) white-flash guard and how the injector overlaps wrappers, holds final frames, ping-pongs tracks, and stamps lint-clean template code onto the master timeline. Does NOT contain the per-transition catalog — see the transition registry for individual transition entries.

Sections in SKILL.md

Stage ground prerequisite (white-flash guard)
How the injector applies a transition
Template placeholders

Key facts

Author: heygen-com (GitHub repo owner)
Repo: heygen-com/hyperframes
Installs on skills.sh: 60,535 as of 2026-11-02
GitHub stars (repo): 77,112 as of 2026-11-02
Last repo commit: 2026-11-02
License: Apache-2.0
Files: 1 file (SKILL.md only)
Status: Marked `internal: true` in its SKILL.md; the README calls the six repo-internal skills excluded from the default install
skills.sh audits: Gen Agent Trust Hub pass, Socket pass, Snyk pass

What it includes

Paint #root so dips do not flash white
The assembled index.html must set an opaque background on `#root`, such as `var(--canvas-deep, var(--canvas, #000))`. Without it the renderer shows its default white page during the dip.
Stage ground prerequisite
Four steps at each scene boundary
Extend the outgoing wrapper to hold its final frame, pull the incoming wrapper earlier to create overlap, reassign tracks as a 0/1 ping-pong, and stamp the template into the master timeline.
How the injector applies a transition
Tokens replaced in each template line
`__OLD__`, `__NEW__`, `__T__`, `__DUR__`, `__DX__`, `__DY__`, and the `__ORIGIN_OUT__` / `__ORIGIN_IN__` pair.
Template placeholders

From the official docs

Questions

What does seam-craft do?

It gives Claude the render-side rules for scene-to-scene seams in HyperFrames videos. The key one is painting the stage so the mid-cut opacity dip does not show a white page.

How do I install it?

Use the install box above. The README says this skill is one of six repo-internal skills left out of the default install, and the skills CLI docs say internal skills only install when INSTALL_INTERNAL_SKILLS=1 is set, so the command sets it. We have not run that command, so check npx skills list afterwards.

Why do I get a white flash at a cut?

The SKILL.md says some templates open a window where the two wrappers' opacity adds up to less than 1, so whatever is behind them shows. If #root has no opaque background, that is the default white page. Setting the background is the fix it gives.

Does it include the list of transitions?

No. The SKILL.md says the per-transition catalog lives in the transition registry, which is not part of this skill. The separate cut-the-curve skill in the same repo holds transition parameters.

Does it run scripts?

The skill bundles no scripts. It mentions assemble-index.mjs as the assembler that emits the background, but that file is not part of this skill.

Information

updated Nov 2, 2026

Repository: heygen-com/hyperframes
Folder: .agents/skills/seam-craft

heygen-com/hyperframes skills.sh

Sources

Docs, issue trackers and discussions this page is built from.

Show all 4

skills CLI troubleshooting and configuration · github.com
skills CLI: creating skills (metadata.internal) · github.com
heygen-com/hyperframes README · github.com
seam-craft SKILL.md · github.com